Adds .NET Core issue template

.github/ISSUE_TEMPLATE/3_BugNetCore.md

@@ -0,0 +1,65 @@
+---
+name: 🌟 .Net Core Bug Report 
+about: For bugs specifically for the **upcoming** .NET Core release of Umbraco, don't use this if you're working with Umbraco version 7 or 8
+labels: project/net-core
+---
+
+ℹ️ If this bug **also** appears on the current version 8 of Umbraco then please [report it as a regular bug](https://github.com/umbraco/Umbraco-CMS/issues/new?template=1_Bug.md), fixes in version 8 will be merged to the .NET Core version.
+
+A brief description of the issue goes here.
+
+<!--
+
+Please fill out the rest of the details in the issue template below. 
+The more details you can give us, the easier it will be for us
+to determine the cause of a problem.
+
+-->
+
+
+Reproduction
+------------
+
+If you're filing a bug, please describe how to reproduce it. Include as much
+relevant information as possible, such as:
+
+### Bug summary
+
+<!--
+    * Write a short summary of the bug
+    * Try to pinpoint it as much as possible
+    * Try to state the _actual problem_, and not just what you _think_ the
+      solution might be.
+-->
+
+### Specifics
+
+<!--
+    * Mention the URL where this bug occurs, if applicable
+    * What version of Umbraco are you using (down to the very last digit!)
+    * What browser and version you are using
+    * Please mention if you've checked it in other browsers as well
+    * Please include *full error messages* and *screenshots* if possible
+-->
+
+### Steps to reproduce
+
+<!--
+    * Clearly mention the steps to reproduce the bug
+-->
+
+### Expected result
+
+<!--
+    * What did you _expect_ that would happen on your Umbraco site?
+    * Describe the intended/desired outcome after you did the steps mentioned.
+-->
+
+### Actual result
+
+<!--
+    * What is the actual result of the above steps?
+    * Describe the behaviour of the bug
+    * Please, please include **error messages** and screenshots. They might mean
+      nothing to you, but they are _very_ helpful to us.
+-->